1. Field
The present disclosure relates generally to communication systems, and more particularly, to a system to support radio link control (RLC) layer handover between wide area network (WAN) supported device to device (D2D) communications and direct D2D communications.
2. Background
Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power). Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency divisional multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.
The wireless communications system may include a plurality UEs and a plurality of evolved NodeBs (eNBs). The UEs may be associated with difference eNBs and the eNBs may be associated with different cells in a WAN. UEs may engage in D2D communications. Such D2D communications may be direct between UEs and/or supported by one or more eNBs in the WAN. Currently, handover of communications across eNBs is enabled using LTE tunneling of the PDCP context from one eNB to another. The LTE tunneling further involves setting up radio bearers in the new cell. Implementation of this handover process for handover between D2D communications and WAN support D2D communications, and back, results in the loss of the RLC layer state and entails a larger overhead and more latency that is necessary for handing off a D2D connection to the WAN or vice versa, especially when the UEs are in RRC connected states in their respective cells (which may be the same cell). As such, a method and apparatus for supporting RLC layer handover between WAN supported D2D communications and direct D2D communications is desired.